Merge pull request #611 from pijyoi/master

update Makefile to include new files
Converted README to markdown + added travis build img
Merge pull request #612 from ulikoehler/markdown

Converted README to markdown
REQ sockets drop replies from unasked peers.

* Add lb_t::sendpipe() that returns the pipe that was used for sending,
  similar to fq_t::recvpipe().
* Add forwarder functions to dealer_t to access these two.
* Add logic to req_t to ignore replies on pipes that are not the one
  where the request was sent.
* Enable test in test_spec_req.
Fix coding style in spec tests.
Merge pull request #608 from ckamm/req-drops-unwanted

REQ sockets drop replies from unasked peers.
Merge pull request #613 from ckamm/coding-style-spec-tests

Fix coding style in spec tests.
Fix intermittent failure in test_spec_req.

There still is a problem when a stale peer's message
arrives at the REQ just after a request was sent to that peer.
Merge pull request #614 from ckamm/fix-spec-req-fail

Fix intermittent failure in test_spec_req.
Disabled last step in test_spec_req so build can complete
README file moved to GitHub format and extension, drop from packaging and default to NEWS file for popup.
Move CMake dependencies together.
Add CMake support for static libraries.
Merge pull request #616 from steve-o/master

Add static libraries to CMake, minor housekeeping.
Merge pull request #615 from hintjens/master

Last step in test_spec_req is still failing; disabled it.
Add get_peer_ip_address utility function

The functon returns string representation of peer's
IP address. We will need this to update ZAP implementation.
Update CURVE mechanism to the latest ZAP revision
Update PLAIN mechanism to the latest ZAP revision
Implement ZAP for NULL mechanism
Merge pull request #617 from hurtonm/zap_updates

Zap updates